Artiva Biotherapeutics (ARTV) said its AlloNK program is moving toward a Phase III trial in refractory rheumatoid arthritis, with management expecting concrete updates on site initiation and enrollment timing before the end of 2024 and a primary readout targeted for the end of 2028.
At the H.C. Wainwright 28th Annual Global Investment Conference, moderated by equity research analyst Emily Bodnar, Chief Executive Fred Aslan outlined the company's plan for a randomized controlled trial of AlloNK, an allogeneic natural killer cell therapy combined with rituximab, against rituximab in patients who have failed two or more distinct biologic drug classes. The planned study will enroll 150 patients across at least 80 sites, with ACR50 response at six months as the primary endpoint. Aslan said enrollment is expected to take about 18 months, and the company's cash is expected to last through completion of Phase III and into 2029.
Artiva, which is based in San Diego, said it raised $300 million and had a market capitalization of about $500 million. The stock had returned 301% over the past year and traded around $10.20, with a real-time snapshot showing $10.31, up 0.88%, or $0.09. The company's beta was 2.2, and management cited a U.S. rheumatoid arthritis market of more than $20 billion.
The Phase III design follows a second-quarter 2024 alignment meeting with the Food and Drug Administration. Aslan said the trial will be a randomized controlled study rather than an open-label design, with rituximab as the comparator. The company is targeting an ACR50 response rate of at least 50% in the refractory population, compared with an approximate 10% to 20% ACR50 benchmark for rituximab. The refractory population is about 25% of rheumatoid arthritis patients who start a biologic and fail two or more distinct drug classes. Aslan said a 50% or higher response rate versus an approved drug at 20% would create a meaningful difference without requiring a very large study, given the refractory population.
In Phase II data, Artiva reported a 71% ACR50 response rate in rheumatoid arthritis, based on five of seven evaluable patients at six months. The company also said its proprietary high-sensitivity B-cell assay detected no B cells in its rheumatoid arthritis patients, with a limit of detection of 0.1 to 0.2 cells per microliter, compared with 5 to 10 cells per microliter for standard rituximab assays. Aslan said the results, combined with observed efficacy, supported the view that AlloNK works significantly better than rituximab.
The company's broader autoimmune basket study has treated more than 70 autoimmune disease patients, while more than 60 oncology patients have been treated. Data presented at EULAR included 21 patients with at least 12 weeks of follow-up. Aslan said updated data are expected at ACR 2024, including at least 20 rheumatoid arthritis patients, of which at least 10 would meet Phase III criteria with more than six months of follow-up, at least 10 Sjögren's syndrome patients, and five scleroderma patients with more than six months of follow-up.
AlloNK is being developed for refractory rheumatoid arthritis and basket indications including Sjögren's syndrome, scleroderma and myositis. The treatment uses 8 billion NK cells per administration, compared with roughly 60 million T cells in regular T-cell regimens. Aslan said the NK-cell approach has not caused cytokine release syndrome (CRS) or ICANS, giving it a safety profile he described as differentiated from T-cell approaches.
Operationally, Artiva said patients have been treated primarily in community rheumatology practices rather than specialized hospital or academic centers. The cells are thawed bedside from a Dewar and connected directly to an IV line, while cyclophosphamide and fludarabine are supplied in IV bags for direct use. Rituximab is administered under standard community practice, without requiring specialized pharmacy infrastructure or liquid nitrogen storage.
Aslan characterized AlloNK as a first-in-class candidate if successful, saying the company should be the first deep B-cell depleting product to reach market and probably the first rheumatoid arthritis approval since RINVOQ was approved in 2019.
